Armor-piercing projectile



W. J. TUCKER.

ARMORPIERCING PROJECTILE.

APPLICATION men JULY 18, 192i.

' Patented Feb. 28,1922.

IHHHU l Wm Jzzcm warrensrarss WILLIAM J. TUCKER, or .wesnnvero v, D ST moron comma.

ABMOR-PIERGING PROJEOTILE- Application filed July 18,

To all whom it may concern:

Be it known that LWVILLIAM J. TUCKER,

a citizen of the United States, and aresident of the city of \Vashington', in the District of Columbia, have invented certain new and useful Improvements in Armor-Piercing Projectiles, of which the following is a specification. 7 My invention relates to armor piercing projectiles and more particularly to the construction of the base thereof.

It has been customary in ballistic tests to have the projectile strike the armor plate at an angle of 90 or as near thereto as possible and if no internalweakness developed, the shell would punch its way through the resistant plate and explode beyond the target.

Recent requirements have, however, made it necessaryjin' ballistic tests to change the angle of impact to an angle which is from .20 to 25 removed from the 90 angle heretofore used or, in other words, at an angle measuring from 70 to 65 to thearmor plate. Considerable difiicultly has been encounteredin successfully putting shells through the test'when fired at such an angle because i will enter the rear edge of the shell comes in contact with the hole torn by its point thereby fracturing the body of the shell and impairing its efiiciency as a bursting charge-carrying medium, because the fracture to the shell body exposes the charge carrying cavity.

The detrimental effect to shells as mentioned hereinbefore is occasioned y the change of axis of the shell as way through the'armor plate. its the shell strikes the armor plate at an angle its point the armor punching 'a hole through the same. As the body of the projectile moves through the hole thus torn the axis of'the shell which primarily was disposed at an angle with respect to the armor plate, tends to assume an angle of 90 with respect to the armor plate. This change of the axis of the shell will throw the rear edge of the shell heavily against the opposite side of the hole in the armor plate whereby-the fracture of the shell hereinbefore mentioned results. Y

It isthe object therefor of my invention to provide means whereby the shell will discardits rearf edge upon penetration of the T armor plate in order to avoid the same con-' tacting or binding as it passes therethrough.

In carrying out my invention the base of the shellisiprovided with a circular groove, which groove extends to a point adjacent the Specification of Letters Patent.

sufliciently to the" rear.

it pushes its- Patented Page, 1922. 1921. SerialNo."85,582. 7'

rear edge of the bandscore. This groove is inthe nature of a weakening groove thereby prov ding a circular predetermined point of fracture for the rear edge of the shell. Thls pie-determined point of fracture is of the explosive charge cavity to eliminate the possibility of the shell* fracturing so as to expose this cavity. jI-Ience' when the rear edge of the shell contacts with the hole inqthe armor plate, the rear edge will be broken off at the point outlined by the disposition of this weakening groove, thereby permitting the; shell to pass through the and allowing the v rear, end of the hole without binding charge-carrying cavity to remain intact. The contact of therear end of the-shell with the hole in the armor plate, as just described, exerts a radial rear end of the shell. This sometimes causes a distortion of the rear edge of the shell which permits the base plug to fall out. By providing the circular groove in the base of the shell the force of the contact of the rear the opening ijn'the edge of the shell with armor plate will not be exerted upon'the pressure upon the portion of theshell bodyimmediately sur- I rounding the base groove will permit the outer section of the shell formed by this groove to give first, before any the rest of the shell body.

It is essentialthat themouth of this culargroove be closed to prevent the gases of the firing charge from entering therein,

inasmuch as these gases might cause pre mature fracture to the base of the projectile; i In order,

of this circular-groove, I provide a ring which forms acontinuation of the flange of faces'of the the base plug. The abutting base plug flange and ofthis clined so that a contact of the the she-ll will ic -auseithe' ring to screws which fasten ring are in{ rear edge of shear off the the rear edg'eof the shell, assuring its fracg plug. This circular therefore, to close the mouth pressure is exerted. upon,

it; to the base plug I flange, thereby causing the ring tobe disture" at the pre-dete'rmined point of weakness.

The various features be made more apparent in the accompany? ing specification and drawings in which;

Fig; 1 shows the base of a projectile constructed in accordance with my invention,

Fig. 2 is a fragmentary elevation, partly in section of the structure shown in Fig. 1,

Fig. 3 is a section of a rear corner of the of my invention will shell, showinga modified form of ring", and 'Fig. 4 is aisimilar yiew of'sti'll another form of ring.

In the drawings the numeral lo'indicates a shell body provided -with. an explosive containipg. cavity. '11 clo'sedibya base plug 12 screw-threadedly engaging the body ofthe shell;

the usual flange 13.. A fuse-seat 1 4; and .a 'fi selplug seat 15 are shown, these being oftheusual construction], The base 16'is preferably counterhored as at 17 toza diamreeted"jgr.oove 21*, A p

indicated'..by-the numeral.22..' In formlng, 25

eter'in. excess of" the diameter of the base plug. fifang'e, for. a purpose to. be more fully hereinafter set. forth.

A; IIOtating rearjed e of the bandscore .isindicated by tli'eQmimralQO.

"In" orderito weaken the rear edge ,of the shell and tojprovidea predetermined pointv offffracture l cut'an annular lnwardly d1- the bottom of whlch is.

the annular' groove 21 the inner wall thereof i'sl sliiouldered'asindicated at.23., The'bottornf22 of this annular; groove, is 111 close.

' proximity to. the reared-gs 20 of theband soorefwhe'reby the shell bodyis weakened cjireumfrent-ially on the line 24,' thereby y; oyiding, the desiredpredetermined pointv I of fracture.

{j Inorderto'close the opening caused bythe1grooye21 and to form in-the base 16 an annular'ffcavity I prov ide a. filler ring 25,

. referably of soft. steel. .Thisring. is provijddfwith an inclined face26 adapted to;

abut a. similarly inclined face formed on the base/plug flange 13'. For unitingthe filler; ring '25' with' the baseplug flanpe 13, 1. pro

ide, a; multiplicity of: i-adia disposed sciewethreaded pins- 27 which project rav v y are'screw thiiaded. intothe base plug flan e13, By

7 p the. filler and the base plug .flan-ge as. indicateda; .radialfipressure on .the-

of the shelldially' i; throngh e' ring 25 iIiCHni'ng the contacting face 0 which .isssuffi cient to: cause affracture to the 1 rear edge. thereof-will simultaneously tend base, qfl;theprojectile,j thereby shearing; ofi' t'ojfor'ce we ring- 25. outwardly free of the s. 27: andiproyidingthe desired. clearancefforiftheiedge ofrthe. 'shell about to be broken-01f;

, been 11us'tmme. ;-In this f rm inemmterbbred theawall thereof. being inclinedcsojifas to.- properly receive the base.

plu'g' flangev with its inclined face 28.; In this; form the extended flange of' the" base The base plug is: provided with band 18 of usual construction ifs-provided. seated in a bandscore 19, the

plug 'flange provided with an annular groove 29. When radialpressure is exerted upon the rear edge of the shell, sufficient to cause afracture, the portion of the flange beyond the circulargroove 29 will be broken off by-i-reason of the same being wealiened;

Thiswillfprovide the necessary clearance for the edge of the" shellto insure its complete fracture. 1 I v r 7 In Fig. 4 still another'modificatigm:oi the filler ring .is. illustrated; In this instance no: positive connection is madebetween the filler ring 25 and: the base plugxfiange 113.

The fillerringis however,.provided withan v inwardly extending lip 30- and the-base fping flange is correspondingly recessed. The len ring25 is insertedin the counterbore li and the base plug is thereafter screwed into po:

sition. Byreason'ofithe. lip some base plug flange v 13' will prevent axial; displacement of the filler ring;25. Upon fracture ofthe rear edgeofthe shell, howeyen, the filler ring, will be displaced. because the pressure against the rear end ofiithe shella which tends to displace the lfiller-fringfifi" 7 willbreakoff the'annular. lip30. When the. projectile of .the f0rm .as described strikes the armor plate, of avessel= atan, angle from. normal, the point of the;

shell will in a usual-manner punch a holeso-that the shell c'anenterv the armor {Asthe body of the. bodyfof the projectile attempts to pass through the-opening, thus formedlthe angle formed by the arm-or'pla te and the aXis of the projectile will; have changed, the

projectile. tending first to swing ou-t'so as to ioo enter at approximatelyQG with respect; to. 7

the armor plate and-- subsequently whipping.

around. so that .its. longitudinalv axis forms: with the armor plate an obtuse angle where previously there had been an acute angle.

This whipping; or. swingingamotion ofthe rear edge of the shell causes; itssideto zon -.tact= with the opening in thez'a-rmor plate',

the force being exerted'in a radial dimction: upon the base of: the shelL, Insteadzof: free tuning, the shel body the, radialpressure.

causes the qrear edge} of the: shell toa b'reaki along the 'line;24 or' along? the predetermined? v of fracture. line of; weakness: is

sufiieiently. tetherear orfzthezburstiingzeharge cavity; sothat the. fracture ofv the shell will, not disturb the. bursting-charge aswon'ld" he the case with shells of. the usual.'colistzruotion.--- W :As hereinhefore stated; the exerted thereby shearing ofi" thepins 27.-

r In, the two mod-'fied forms Definer.- rings? illustrated theconstruction is such that upon 'fracture of the-rear edgeofthe shell? the upon the rear edge of the shell WillIi'fieI-Idj -to displacethefiller'ringj25 by. slidinguthe I same rea-rwardly and axially with respect to the shell; by reason of; thei-nclined faice '26,

ring will be discarded in order to provide a clearance necessary for a positive fracture of this rear edge of the shell.

Also it should be noted that the pressure which causes a fracture to the rear edge of the shell, will not be exerted directly upon that portion of the shell body which immediately surrounds the base plug. The annular weakening groove 21 so separates the outer portion of the base of the projectile from the inner portion which immediately surrounds the base plug, that the pressure exerted on the outer portion will in most instances break the same olf from the projectile before causing a pressure upon the inner portion of the shell which is sufficient to disturb the base plug.

The prime feature of my invention resides in the provision of a weakening groove so disposed in the base of the projectile as to lie adjacent the rear edge of the bandscore. It is obvious that various means such as filler rings or extensions of the base plug flange may be employed for closing the mouth of this annular weakening groove. The essential feature of this filling means in each instance being that it be capable of being discarded quickly when the fracture of the rear edge of the shell occurs. 7

In constructing the annular groove 21 a tool of greater width is used to cut th groove down to the shoulder 23 and thereafter a tool of smaller guage is used to cut the groove to its bottom, 22. It is obvious that if desired a groove of the same thickness from its mouth to its base may be formed.

Having thus described my invention, what I claim is:

' of weakness from t 1. An armor piercing projectile characterized by a line of weakness from the bandscore to the base, said line of Weakness formed by an upwardly directed groove in the shell base, thereby weakening the shell body on a line from the inner rear edge of the band score to the inner end of the groove.

2. An armor piercing projectile characterized by the provision of an' annular groove in the shell base, said groove cooperating with the rear edge of the bandscore,

the distance between said annular grooveand the inner rear edge of said bandscore being less than the minimum distance from weakening groove, the edge of said integral ring being inclined. V

4. An armor piercing projectile having a flanged base plu characterized by a line die bandscore to the base, said line of weakness being formed by an upwardly directed. groove in the shell base,

thereby weakening the shell body on a line from the inner rear edge of the band score to the inner end of the groove and a-filler ring secured to the flange of said base plug and covering the mouth of said groove.

l VILLIAM J TUCKER. 

